Web edition: October 8, 2007
Print edition: October 13, 2007; Vol.172 #15 (p. 239)

Another idea blown . . .

Conservation by America is not going to decrease global warming ("Asian Forecast: Hazy, Warmer—Clouds of pollution heat lower atmosphere," SN: 8/4/07, p. 68). We need to imitate known global-cooling events, such as the Krakatoa volcano explosion, which spread sunlight-reflecting dust into the stratosphere in 1883. A hydrogen bomb exploded inside a ship full of white clay could be a first step.

Daniel Shanefield
Honolulu, Hawaii

Recent research suggests that cooling Earth by injecting large amounts of aerosols high in the atmosphere could cause average rainfall worldwide to decrease dramatically, as it did for more than 16 months after the eruption of Mount Pinatubo in 1991 (SN: 8/25/07, p. 125).—S. Perkins

. . . or out the window?

Based on the Environmental Protection Agency's Web resources on radon, I find that the decreases in radon levels in the summer are unlikely to be caused by a lack of air currents from less temperature differential in houses ("Beware summer radon-test results," SN: 8/11/07, p. 94). The EPA states that an open window can be effective in reducing radon levels. And when are people more likely to open their windows? In the summer.

Joseph Esquibel
Madison, Wis.

Leave the bottle

Recent reports of plastics such as dioxin and now bisphenol A ("Bad for Baby: New risks found for plastic constituent," SN: 8/11/07, p. 84) make me wonder if there are any Alzheimer's-linked aluminum ions or atoms or whatever floating around in our soda cans. Those glass bottles from yesteryear are starting to look very wholesome.

Linda Zimmerman
Torrance, Calif.

Upside of downhill

Osteocalcin ("Skeletal Discovery: Bone cells affect metabolism," SN: 8/11/07, p. 83) may well be the answer to the startling, nearly three-times-stronger glucose control observed in downhill walkers, compared with people walking uphill (SN: 12/11/04, p. 380). The eccentric exertion of downhill walking could be stimulating more osteocalcin release from osteoblasts. Members of our burgeoning prediabetic civilization may be inspired to generate their own osteocalcin by walking down hills, stairs, and even treadmills.

Jay Chapman
Pulaski, N.Y.